Semiconductor devices (e.g., integrated circuits) can integrate a number of different components, including different transistor types. For instance, bipolar transistors and metal oxide semiconductor (MOS) transistors (including complementary MOS (CMOS) transistors) can be integrated on a single substrate to form BiCMOS devices. Such integration designs allow one to take advantage of selected properties of the components. E.g., bipolar transistors can be used in some analog operations requiring high speed or greater drive currents, while CMOS transistors can be used in some digital operations requiring low power dissipation. The push to increase transistor density in devices results in a smaller size and closer proximity of transistors.